Name GEOL 104 Dinosaurs A Natural History Smithsonian Assignment I Life on Land before the Dinosaurs and the Dinosaurs Themselves DUE October 27 Every man is a valuable member of society who by his observations researches and experiments procures knowledge for men James Smithson 1765 1829 a British natural historian whose legacy of over 500 000 was given to the government of the United States of America for the creation of an Establishment for the increase and diffusion of knowledge the Smithsonian Institution The Smithsonian Institution s National Museum of Natural History NMNH has one of the largest collections of dinosaur and other fossils in the world The Smithsonian museums are free hours for the NMNH are 10 am to 5 30 pm 7 days a week You can take the Metro from the College Park Station to any of a number of stations near the Museum The quickest route is the Green Line from the UMd College Park Station to Archives Navy Memorial you don t have to change trains and the NMNH is just on the other side of the Archives Building For this exercise you may wish to bring along the anatomy sheets handed out in class You may work in teams and discuss your answers however ALL WORK YOU TURN IN MUST BE YOUR OWN I have caught and reported a number of students in the past you have cheated by copying each other s work please don t make me do that again To comply with University Senate regulations please sign the following so that you may receive credit for this assignment I pledge on my honor that I have not given or received any unauthorized assistance on this assignment Signature UID Date NOTE Use your OWN OBSERVATIONS in order to answer the questions This package works as sort of a self guided tour It will start in the Conquest of the Land exhibit and end up in the Dinosaur Hall 1 Name PART I LIFE ON LAND BEFORE THE DINOSAURS For this exercise you will probably find the anatomy sheets handed out in class also available on the website a useful guide in identifying the homologous bones in these different animals On the first floor find the exhibit called Conquest of the Land also labeled Fossil Plants on some maps These exhibits discuss the colonization of land by plants and early stegocephalians amphibians in the old sense Find the case labeled Amphibians The Vertebrates Take to Land and locate the model of the crossopterygian fish Eusthenopteron Compare the front pectroral fin to the images below 1 The front pectoral fin of Eusthenopteron more closely resembles fin a b Find the mounted skeleton of Eryops a large stegocephalian 2 Based on the shape of its teeth do you think that it ate fish and meat or that it ate plants 3 What evidence led to you to your answer in question 2 Note also the skeleton of Pelosaurus laticeps a possible tadpole of Eryops 2 Name In the center of this room is a set of fossils of the stegocephalian Buettneria perfecta that were found together 4 Based on the text hanging from the ceiling what is the likely reason for the particular grouping and position of the bones Head for the early reptiles really early amniotes exhibits look for an Allosaurus foot in a glass cylinder to find your way Below are cartoons of three major skull types found in amniotes They differ by the patterns of the temporal fenestrae the openings for jaw muscle attachments Anapsid no temporal fenestrae Synapsid infratemporal fenestra Diapsid supra and infratemporal fenestrae Find the skeleton of Diadectes in the display case labeled Stem Reptiles This creature is very close to the base of Amniota some paleontologists think that it is a true amniote while others think that it lies just outside that group 5 What skull type does Diadectes have anapsid synapsid diapsid Extra Credit Paleontologists agree that Diadectes wasn t a flesh eater What feature s of the teeth suggests a nonmeaty diet for this animal 3 Name Find the exhibit labeled The First Wave of Reptilian Diversity featuring the skeletons of Dimetrodon grandis Edaphosaurus boanerges and Cotylorhynchus romeri In modern classifications these animals would not be considered reptiles although it is fair to say that they were part of the first wave of amniote diversity Dimetrodon with the largest skull is probably the best one to look out for the next two questions 6 These animals have the anapsid synapsid diapsid skull type 7 These animals do do not have an antorbital fenestra Extra Credit In which of these three animals are the teeth most differentiated in size and shape between the different parts of the jaws Dimetrodon Edaphosaurus Cotylorhynchus The ancestral state for limb postures in tetrapods is sprawling limbs oriented out to the sides the derived state is parasagittal limbs oriented downward Indicate the limb posture of the following tetrapods 8 Dimetrodon Sprawling Parasagittal 9 Edaphosaurus Sprawling Parasagittal 10 Diadectes Sprawling Parasagittal 11 Cotyloryhnchus Sprawling Parasagittal Find the exhibit labeled Cynodont Flesh Eaters On display are the skull of the large Cynognathus crateronotus and the much smaller skeleton of Thrinaxodon liorhinus 12 These taxa have a anapsid synapsid diapsid skull type The primitive condition for tetrapod teeth is undifferentiated the same shaped teeth from the front of the snout to the back the derived state is differentiated specialized teeth in different parts of the jaws 13 The jaws of the cynodonts show undifferentiated differentiated teeth Find the case labeled Early Reptilian Plant Eaters again these are actually synapsids not true reptiles The particular type here are various dicynodonts Find the large skull of Aulacephalodon baini 14 How many teeth total are present in the skulls of these animals 4 Name Move on to the exhibit un creatively named Non Dinosaurs Find the skeleton of the Triassic reptile Trilophosaurus buettneri 15 The limbs of Trilophosaurus are sprawling parasagittal Look behind you at the skeletons of dicynodonts and back at Edaphosaurus Dimetrodon and Cotylorhynchus Now look back at Trilophosaurus 16 Out of all of these creatures which would you suspect was the fastest Why PART II THE DINOSAURS Turn left and walk towards the Dinosaur Hall You ll find the right pelves of Stegosaurus and Allosaurus on display on the left wall 17 In these two dinosaurs the acetabulum hip socket is covered by a sheet of bone open 18 In which of these two dinosaurs is the main shaft of the pubis pointing backwards Allosaurus Stegosaurus both neither 19 These pelves are shown in left